title: A genome-wide screen for ethylene-induced ethylene response factors (ERFs) in hybrid aspen stem identifies ERF genes that modify stem growth and wood properties.
abstract: Ethylene Response Factors (ERFs) are a large family of transcription factors that mediate responses to ethylene. Ethylene affects many aspects of wood development and is involved in tension wood formation. Thus ERFs could be key players connecting ethylene action to wood development. We identified 170 gene models encoding ERFs in the Populus trichocarpa genome. The transcriptional responses of ERF genes to ethylene treatments were determined in stem tissues of hybrid aspen (Populus tremula × tremuloides) by qPCR. Selected ethylene-responsive ERFs were overexpressed in wood-forming tissues and characterized for growth and wood chemotypes by FT-IR. Fifty ERFs in Populus showed more than five-fold increased transcript accumulation in response to ethylene treatments. Twenty-six ERFs were selected for further analyses. A majority of these were induced during tension wood formation. Overexpression of ERFs 18, 21, 30, 85 and 139 in wood-forming tissues of hybrid aspen modified the wood chemotype. Moreover, overexpression of ERF139 caused a dwarf-phenotype with altered wood development, and overexpression of ERF18, 34 and 35 slightly increased stem diameter. We identified ethylene-induced ERFs that respond to tension wood formation, and modify wood formation when overexpressed. This provides support for their role in ethylene-mediated regulation of wood development.
authors.affiliation: Department of Biosciences, Division of Plant Biology, University of Helsinki, FI-00014, Helsinki, Finland.
authors.forename: Jorma
authors.initials: J
authors.lastname: Vahala
authors.affiliation: Umeå Plant Science Center, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-90183, Umeå, Sweden.
authors.forename: Judith
authors.initials: J
authors.lastname: Felten
authors.affiliation: Umeå Plant Science Center, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-90183, Umeå, Sweden.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Love
authors.affiliation: Umeå Plant Science Center, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-90183, Umeå, Sweden.
authors.forename: András
authors.initials: A
authors.lastname: Gorzsás
authors.affiliation: Umeå Plant Science Center, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-90183, Umeå, Sweden.
authors.forename: Lorenz
authors.initials: L
authors.lastname: Gerber
authors.affiliation: Department of Biosciences, Division of Plant Biology, University of Helsinki, FI-00014, Helsinki, Finland.
authors.forename: Airi
authors.initials: A
authors.lastname: Lamminmäki
authors.affiliation: Department of Biosciences, Division of Plant Biology, University of Helsinki, FI-00014, Helsinki, Finland.
authors.forename: Jaakko
authors.initials: J
authors.lastname: Kangasjärvi
authors.affiliation: Umeå Plant Science Center, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-90183, Umeå, Sweden.
authors.forename: Björn
authors.initials: B
authors.lastname: Sundberg
mesh_terms: D000595:Amino Acid Sequence; D000598:Amino Acids, Cyclic / Q000494:pharmacology; D005030:Ethylenes / Q000494:pharmacology*; D015870:Gene Expression; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D018745:Genome, Plant / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018547:Plant Stems / Q000033:anatomy & histology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D030821:Plants, Genetically Modified; D032107:Populus / Q000033:anatomy & histology / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014934:Wood / Q000033:anatomy & histology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D052584:Xylem / Q000033:anatomy & histology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism
chemical_list: D000598:Amino Acids, Cyclic; D005030:Ethylenes; D010940:Plant Proteins; D014157:Transcription Factors; C023863:1-aminocyclopropane-1-carboxylic acid; C036216:ethylene
keywords: Ethylene Response Factor (ERF); Populus; ethylene; tension wood; transcript analysis; wood development; xylem